1. Field of the Invention
The present invention relates to zoom lenses, especially to zoom lenses with low cost, high zoom ratio, small size, and good image quality.
2. Description of the Prior Art
Image-capturing devices, such as digital cameras or digital camcorders, typically employ a zoom lens and an image sensor to collect an image beam of an object, in which the zoom lens focuses the image beam on the image sensor, which then turns analog signals of the image beam into digital signals for following processing, transmitting, and storage.
Typically, the zoom lens of the image-capturing devices consists of several lenses or prisms. To offer competitive prices and lower the weight, plastic lenses are employed as possible to replace glass lenses; however, the plastic lenses come with the disadvantages of moisture and light absorption, and conflict may appear between small size, high zoom ratio, and good image quality when reducing the cost.
Therefore, it would be advantageous to provide novel zoom lenses having advantages of compact size, high zoom ratio, and good image quality when reducing the cost.